Adsorption properties of kaolinite-based nanocomposites for Fe and Mn pollutants from aqueous solutions and raw ground water: kinetics and equilibrium studies
| Autor: | M. E. M. Hassouna, Mostafa R. Abukhadra, Mohamed Shaban, Fadya M. Nasief |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Starch Iron Health Toxicology and Mutagenesis Inorganic chemistry 02 engineering and technology 010501 environmental sciences 01 natural sciences Endothermic process Nanocomposites Water Purification Diffusion symbols.namesake chemistry.chemical_compound Adsorption Environmental Chemistry Kaolinite Freundlich equation Kaolin Groundwater 0105 earth and related environmental sciences Ions Manganese Aqueous solution Nanocomposite Langmuir adsorption model General Medicine Hydrogen-Ion Concentration 021001 nanoscience & nanotechnology Pollution Solutions Kinetics chemistry symbols Thermodynamics 0210 nano-technology Water Pollutants Chemical |
| Zdroj: | Environmental Science and Pollution Research. 24:22954-22966 |
| ISSN: | 1614-7499 0944-1344 |
| DOI: | 10.1007/s11356-017-9942-0 |
| Popis: | Raw kaolinite was used in the synthesis of metakaolinite/carbon nanotubes (K/CNTs) and kaolinite/starch (K/starch) nanocomposites. Raw kaolinite and the synthetic composites were characterized using XRD, SEM, and TEM techniques. The synthetic composites were used as adsorbents for Fe and Mn ions from aqueous solutions and natural underground water. The adsorption by the both composites is highly pH dependent and achieves high efficiency within the neutral pH range. The experimental adsorption data for the uptake of Fe and Mn ions by K/CNTs were found to be well represented by the pseudo-second-order kinetic model rather than the intra-particle diffusion model or Elovich model. For the adsorption using K/starch, the uptake results of Fe ions was well fitted by the second-order model, whereas the uptake of Mn ions fitted well to the Elovich model rather than pseudo-second-order and intra-particle diffusion models The equilibrium studies revealed the excellent fitting of the removal of Fe and Mn ions by K/CNTs and Fe using K/starch with the Langmuir isotherm model rather than with Freundlich and Temkin models. But the adsorption of Mn ions by K/starch is well fitted with Freundlich rather than Temkin and Langmuir isotherm models. The thermodynamic studies reflected the endothermic nature and the exothermic nature for the adsorption by K/CNTs and K/starch nanocomposites, respectively. Natural ground water contaminated by 0.4 mg/L Fe and 0.5 mg/L Mn was treated at the optimum conditions of pH 6 and 120 min contact time. Under these conditions, 92.5 and 72.5% Fe removal efficiencies were achieved using 20 mg of K/CNTs and K/starch nanocomposites, respectively. Also, K/CNTs nanocomposite shows higher efficiency in the removal of Mn ions as compared to K/starch nanocomposite. |
| Databáze: | OpenAIRE |
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